露点的两个重要特征:

1. Dewpoint is not temperature dependent parameter 露点温度与气体温度无关

• the measurement is not changed if the gas temperature change 如果气体温度变化，露点温度不变

– process gas can be cooled before measurement 流程气体通常在测量前冷却

2. Dewpoint is pressure dependent parameter 露点温度是与压力相关的参数

• when pressure increases also dewpoint value increases 压力升高时露点升高

– in pressurized systems Vaisala recommends to measure in gas pressure, not in ambient pressure 对于带压环境，建议带压测量露点，不建议采样常压测量。